The counting of cells in a blood sample is an important diagnostic tool.
An example of a known approach to counting cells in a blood sample is flow cytometry. In flow cytometry, a blood sample flows through a capillary such that cells pass one by one in front of a light source and detection arrangement. The reflected and/or transmitted light is detected and analysed. The characteristics of the detected light depend on characteristics of the cells in the sample and how they are stained and, in this way, cells are classified and counted. However, no morphological information for the cells is obtained using flow cytometry. Morphological analysis can be carried out on a blood sample by sandwiching the sample between two slides and investigating the sample under a microscope. Automated systems for cell counting are known which use cartridges of pre-prepared slides. Such slides need to be prepared manually for each sample to be analysed. This is a time-consuming process, in spite of the partial automation.
It would be desirable to have a system for cell counting in which the morphological information of cells is not lost but instead is used to improve the accuracy of the cell counting process and which, further, does not require the preparation of slides.